The best approach to answering this question:
Focus on the part of you which makes you the best candidate for the position. Talk first about your preparation for the role and then focus in tightly on what makes you the best candidate for the role. Use a quick overall summary, then use laser focus on the role itself. Keep your initial answer short, about 2-3 minutes at most, then pause to give the interviewer the opportunity to either: a) ask a different question; or b) ask a clarifying or detail question drilling into specifics around your answer. When you pause, some interviewers will simply pause and/or nod as an indicator for you to continue. If that happens, start drilling into the details and examples. Also, be prepared for potential interruptions along the way, as many interviewers use this question as a way to bring up areas of interest where they can drill down further.